Leonardo da Vinci’s device that used a rotating screw to suggest vertical flight is called the aerial screw.
Leonardo drew the aerial screw in the Codex Atlanticus around 1489. The design has a large helical surface made from reed, linen, and wire, mounted on a framework. His note suggests that if the screw were turned rapidly, it could rise by pressing against the air, much as a screw advances through a solid material.
The sketch is frequently described as a helicopter ancestor, but it was not a working helicopter. Human muscles could not supply enough power to rotate the large screw, and the design lacked the powered rotor, control systems, and lightweight engine needed for practical flight.
The aerial screw shows Leonardo reasoning by analogy. He compared air to a substance that could be engaged by a spiral surface. Modern helicopter rotors operate through aerodynamic lift rather than simply twisting through air like a conventional screw, so the resemblance is conceptual rather than mechanically exact.